Damper bumper cap with labyrinth air passageway

Abstract

A damper bumper cap for covering the rod side end of the damper tube containing a piston rod seal and for retaining a dust cover on the damper tube. The cap includes a side wall positioned in contact with the damper tube, an end wall that extends radially inwardly over the piston rod seal, and an annular skirt that is spaced radially outward of the side wall. First and second groups of connection wall segments extend radially between the side wall and the annular skirt at different heights to define vent openings in the spaces between the connection wall segments in the first and second groups of connection wall segments. The vent openings thus provide a plurality of tortuous airflow paths through the cap at circumferentially spaced locations.

What is claimed is: 
     
       1. A damper system for a vehicle, comprising:
 a damper tube extending longitudinally between a rod side end and a closed end; 
 a piston rod extending into the rod side end of the damper tube along a longitudinal axis; 
 a piston assembly coupled to the piston rod and slidably fitted in the damper tube; 
 a piston rod seal positioned radially between the piston rod and the rod side end of the damper tube; 
 a dust cover extending annularly about the rod side end of the damper tube and an exposed portion of the piston rod that is positioned outside the damper tube; and 
 a cap positioned over the rod side end of the damper tube and the piston rod seal, the cap including a side wall positioned in contact with and extending annularly about the rod side end of the damper tube, an end wall extending radially inwardly from the side wall and over at least a portion of the piston rod seal, an annular skirt spaced radially outward of the side wall relative to the longitudinal axis, and a connection wall extending between the side wall and the annular skirt, the cap and the dust cover cooperating to define an inner chamber around a portion of the piston rod, the cap and dust cover being in sealing engagement with one another, wherein the end wall of the cap includes a rod aperture through which the piston rod extends and wherein the connection wall of the cap includes vent openings between the annular skirt and the side wall that define a plurality of tortuous airflow paths through the cap that vent the inner chamber to a space outside the dust cover; 
 wherein the cap includes a flange that extends radially outwardly from the annular skirt relative to the longitudinal axis and wherein the dust cover includes an annular groove that receives the flange of the cap such that air flow cannot travel between the dust cover and the annular skirt of the cap. 
 
     
     
       2. The damper system of  claim 1 , wherein the side wall of the cap extends longitudinally from the end wall to a side wall end, the connection wall includes a first group of connection wall segments and a second group of connection wall segments that are arranged at different heights relative to the side wall end, and the vent openings are defined between the connection wall segments in the first group of connection wall segments and the connection wall segments in the second group of connection wall segments. 
     
     
       3. The damper system of  claim 2 , wherein each of the connection wall segments in the first group of connection wall segments and the second group of connection wall segments has a limited circumferential extent of 90 degrees or less relative to the longitudinal axis. 
     
     
       4. The damper system of  claim 2 , wherein the connection wall segments in the first group of connection wall segments and the second group of connection wall segments are perpendicular to the annular skirt and the side wall. 
     
     
       5. The damper system of  claim 2 , wherein the connection wall segments in the first group of connection wall segments slope towards the end wall moving radially from the annular skirt to the side wall and the connection wall segments in the second group of connection wall segments slope towards the side wall end moving radially from the annular skirt to the side wall. 
     
     
       6. The damper system of  claim 1 , wherein the side wall of the cap extends longitudinally from the end wall to a side wall end, the connection wall includes first and second connection wall segments that are arranged at different heights relative to the side wall end, and the vent openings are defined between the first and second connection wall segments. 
     
     
       7. The damper system of  claim 6 , wherein each connection wall segment of the first and second connection wall segments has a limited circumferential extent of 180 degrees or less. 
     
     
       8. The damper system of  claim 1 , wherein the piston rod extends longitudinally between a first end and a second end, the first end of the piston rod supporting a jounce bumper, the second end of the piston rod coupled to the piston assembly, and the cap protecting the piston rod seal from contact with the jounce bumper when the damper system is in a compressed state. 
     
     
       9. A damper system for a vehicle, comprising:
 a damper tube extending longitudinally between a rod side end and a closed end; 
 a piston rod extending into the rod side end of the damper tube along a longitudinal axis; 
 a piston assembly coupled to the piston rod and slidably fitted in the damper tube; 
 a piston rod seal positioned radially between the piston rod and the rod side end of the damper tube; 
 a dust cover extending annularly about the rod side end of the damper tube and an exposed portion of the piston rod that is positioned outside the damper tube; and 
 a cap positioned over the rod side end of the damper tube and the piston rod seal, the cap including a side wall positioned in contact with and extending annularly about the rod side end of the damper tube, an end wall extending radially inwardly from the side wall and over at least a portion of the piston rod seal, an annular skirt spaced radially outward of the side wall relative to the longitudinal axis, and a connection wall extending between the side wall and the annular skirt, the cap and the dust cover cooperating to define an inner chamber around a portion of the piston rod, wherein the end wall of the cap includes a rod aperture through which the piston rod extends and wherein the connection wall of the cap includes vent openings between the annular skirt and the side wall that define a plurality of tortuous airflow paths through the cap that vent the inner chamber to a space outside the dust cover, wherein the annular skirt extends longitudinally between first and second skirt ends, a first valley region is defined by the first skirt end and the connection wall and the side wall, a second valley region is defined by the second skirt end and the connection wall and the side wall end, and the plurality of tortuous airflow paths extend between the first and second valley regions. 
 
     
     
       10. A damper system for a vehicle, comprising:
 a damper tube extending longitudinally between a rod side end and a closed end; 
 a piston rod extending into the rod side end of the damper tube along a longitudinal axis; 
 a piston assembly coupled to the piston rod and slidably fitted in the damper tube; 
 a piston rod seal positioned radially between the piston rod and the rod side end of the damper tube; 
 a dust cover extending annularly about the rod side end of the damper tube and an exposed portion of the piston rod that is positioned outside the damper tube; and 
 a cap positioned over the rod side end of the damper tube and the piston rod seal, the cap including a side wall positioned in contact with and extending annularly about the rod side end of the damper tube, an end wall extending radially inwardly from the side wall and over at least a portion of the piston rod seal, an annular skirt spaced radially outward of the side wall relative to the longitudinal axis, and a connection wall extending between the side wall and the annular skirt, the cap and the dust cover cooperating to define an inner chamber around a portion of the piston rod, wherein the end wall of the cap includes a rod aperture through which the piston rod extends and wherein the connection wall of the cap includes vent openings between the annular skirt and the side wall that define a plurality of tortuous airflow paths through the cap that vent the inner chamber to a space outside the dust cover, wherein the side wall of the cap includes an inside surface that is cylindrical in shape, smooth, and arranged in an interference fit with the damper tube such that air flow cannot travel between the damper tube and the inside surface of the side wall. 
 
     
     
       11. A damper system for a vehicle, comprising:
 a damper tube extending longitudinally between a rod side end and a closed end; 
 a piston rod extending into the rod side end of the damper tube along a longitudinal axis; 
 a piston assembly coupled to the piston rod and slidably fitted in the damper tube; 
 a piston rod seal positioned radially between the piston rod and the rod side end of the damper tube; 
 a dust cover extending annularly about the rod side end of the damper tube and an exposed portion of the piston rod that is positioned outside the damper tube; and 
 a cap positioned over the rod side end of the damper tube and the piston rod seal, the cap including a side wall positioned in contact with and extending annularly about the rod side end of the damper tube, an end wall extending radially inwardly from the side wall and over at least a portion of the piston rod seal, an annular skirt spaced radially outward of the side wall relative to the longitudinal axis, and a connection wall extending between the side wall and the annular skirt, the cap and the dust cover cooperating to define an inner chamber around a portion of the piston rod, wherein the end wall of the cap includes a rod aperture through which the piston rod extends and wherein the connection wall of the cap includes vent openings between the annular skirt and the side wall that define a plurality of tortuous airflow paths through the cap that vent the inner chamber to a space outside the dust cover, wherein the end wall includes an inner surface with radially extending channels and the side wall includes side wall openings that are disposed in fluid communication with the radially extending channels on the inner surface of the end wall. 
 
     
     
       12. A damper system for a vehicle, comprising:
 a damper tube extending longitudinally between a rod side end and a closed end; 
 a piston rod extending along a longitudinal axis between first and second piston rod ends, the second piston rod end disposed inside the damper tube; 
 a jounce bumper supported on the first piston rod end; 
 a piston assembly coupled to the second piston rod end and slidably fitted in the damper tube; 
 a piston rod seal positioned radially between the piston rod and the rod side end of the damper tube; 
 a dust cover extending annularly about the rod side end of the damper tube and an exposed portion of the piston rod that is positioned outside the damper tube; and 
 a cap positioned over the rod side end of the damper tube and the piston rod seal, the cap and the dust cover cooperating to define an inner chamber, the cap including a side wall positioned in contact with and extending annularly about the rod side end of the damper tube, an end wall extending radially inwardly from the side wall and over at least a portion of the piston rod seal, an annular skirt spaced radially outward of the side wall relative to the longitudinal axis, a first group of connection wall segments extending radially between the side wall and the annular skirt, a second group of connection wall segments extending radially between the side wall and the annular skirt, and a plurality of vent openings axially extending through an end face of the cap opposite the end wall and being defined between the connection wall segments in the first group of connection wall segments and the connection wall segments in the second group of connection wall segments that create a plurality of tortuous airflow paths through the cap at circumferentially spaced locations that vent the inner chamber to a space outside the dust cover. 
 
     
     
       13. The damper system of  claim 12 , wherein the side wall of the cap extends longitudinally from the end wall to a side wall end and wherein the connection wall segments in the first group of connection wall segments are arranged at a different height than the connection wall segments in the second group of connection wall segments relative to the side wall end. 
     
     
       14. The damper system of  claim 12 , wherein the connection wall segments in the first group of connection wall segments and the second group of connection wall segments extend from the side wall at a 90 degree angle. 
     
     
       15. The damper system of  claim 12 , wherein the connection wall segments in the first group of connection wall segments and the second group of connection wall segments extend from the side wall at an oblique angle.